A connector, which is used to supply electric power, is provided with a power pin or a power contact for supplying high electric current. While the electric power is supplied, high electric current flows from the connector to a mating connector, which is mated with the connector, through the power pin or the power contact. It is very dangerous if a mated state, where the connector and the mating connector are mated with each other, is released while the electric power is supplied. Therefore, this type of connectors is generally provided with a structure which prevents the mated state from being released when the electric power is supplied.
For example, the connector provided with the aforementioned structure is disclosed in Patent Document 1 or Patent Document 2, contents of which are incorporated herein by reference. The connector of Patent Document 1 comprises a push-type solenoid which has an electric coil and a plunger driven by the electric coil. The connector further comprises an operation lever operable to release the mated state. The operation lever is formed with a hole. While the electric power is supplied, the electric coil drives the plunger so that the plunger protrudes by a predetermined amount. While the electric power is supplied, the protruding part of the plunger is inserted in the hole of the operation lever so that the operation lever is prevented from being operated. The connector of Patent Document 2 comprises a push-type solenoid similar to the push-type solenoid of Patent Document 1, and a release lever which is formed with a hole. While the electric power is supplied, the plunger is inserted in the hole of the release lever to prevent the release lever from being moved so that the mated state is prevented from being unintentionally released.